Modern automobiles are commonly equipped with rain sensors that are configured to measure rainfall on an automobile's windshield. Measured rainfall can be used to automatically activate and vary the speed of an automobile's windshield wipers and/or to control various other systems in an automobile (e.g., a traction control system).
A typical automobile rain sensor includes light emitting elements (e.g., light emitting diodes), input lenses adapted to collimate light emitted by the light emitting elements and to direct the collimated light toward a windshield at an oblique angle, output lenses adapted to receive an amount of the collimated light that is reflected off of the windshield and to focus the light, and light detecting elements (e.g., a photodiodes) that are adapted to receive the focused light from the output lens and to convert the received light into electrical output signals. When an outer surface of a windshield is wet, the amount of light emitted by the light emitting element that is reflected off of the windshield and received by the light detecting element is generally attenuated relative to when the windshield is dry. Thus, a relatively large electrical output from the light detecting element may be associated with a relatively dry windshield, indicating no rainfall or light rainfall, while a relatively smaller electrical output from the light detecting element may be associated with a relatively wet windshield, indicating heavier rainfall.
Due to the number, size, and position of input and output lenses of conventional rain sensors, only a small portion of light emitted by a light emitting element of a rain sensor is collimated, reflected, focused, and received at a light detecting element. For example, in a conventional rain sensor, each light emitting element is typically associated with a single input lens that receives and collimates only a relatively small portion of a light emitting element's total output. Thus, conventional rain sensors are generally inefficient.
Modern automobiles are also commonly equipped with solar radiation sensors that are configured to measure solar radiation cast on an automobile's windshield. Measured solar radiation can be used to automatically control the function of an automobile's heating, ventilation, and air conditioning (HVAC) system, for example. Conventional solar radiation sensors typically employ one or two light detecting elements (e.g., photodiodes) disposed adjacent an interior surface of an automobile's windshield for measuring solar radiation cast thereon, thus providing only one or two “zones” of solar radiation detection. This limited number of detection zones may provide an inaccurate measurement of solar radiation entering an automobile's cabin, which may result in inappropriate manipulation of an automobile's HVAC system.
It is with respect to these and other considerations that the present improvements may be useful.